Borescope utilizing a right frustum or a cone as reflector

ABSTRACT

A body is mounted on one end of an elongated handle with which the body can be positioned within the bore of a workpiece. An image of the walls of the bore is reflected by an external surface of the body with light from a source mounted in the handle. The body is also sized to simultaneously function as a dimension gauge for the bore.

United States Patent Inventor John A. Mathews Tulsa, Okla.

Oct. 17, 1969 Oct. 5, 1971 Combustion Engineering, Inc.

New York, N.Y.

Appl. No. Filed Patented Assignee BORESCOPE UTILIZING A RIGHT FRUSTUM OR [56] References Cited UNITED STATES PATENTS 1,874,571 8/1932 Mitchell 240/218 3,221,593 12/1965 Ferris 356/241 FOREIGN PATENTS 110,148 5/1925 Switzerland 130,207 l/l929 Switzerland Primary Examiner-Ronald L. Wibert Assistant Examiner-Orville B. Chew, ll] Attorney-Arthur L. Wade ABSTRACT: A body is mounted on one end of an elongated handle with which the body can be positioned within the bore of a workpiece. An image of the walls of the bore is reflected by an external surface of the body with light from a source mounted in the handle. The body is also sized to simultaneously function as a dimension gauge for the bore.

PATENIEI] um 5 IHYI INVENTOR JOHN A. MATHEWS ATTORNEY BORESCOPE UTILIZING A RIGHT FRUS'IUM OR A CONE AS REFLECTOR BACKGROUND OF THE INVENTION 1. Field ofthe Invention The instant invention relates to visual inspection of holes whose walls are located awkwardly for normal observations. More specifically, the invention relates to utilizing a manually manipulated mirror with an associated light source to easily bfing the walls of holes into view, the body of the mirror simultaneously serving as a sizing gauge.

2. Description of the Prior Art Machined and cast walls of holes and crevices of manufactured devices are often difficult to view directly. Viewing of these walls is often necessary to inspect them for flaws and in regularities. l

A dental mirror and hand flashlight are presently used for the laborious task of inspection. The small dental mirror is limited in its view and awkward to coordinate with a flashlight to reflect a plenary image of hole walls to the eye.

SUMMARY OF THE INVENTION The present invention contemplates providing a body with a mirrorlike surface on its periphery. The body is suspended by a handle which includes a light bulb spaced from the surface.

The surface is inclined from the walls of a hole adjacent the body to reflect light from the walls to the eye of an inspector. As the body and light are moved in a path parallel the inspected walls, a comprehensive view of the walls is obtained by the inspector positioning his eye in the parallel path. The body isalso sized to function as a dimensional gauge for the hole.

Other objects, advantages and features of this invention will become apparent to one skilled in the art upon consideration of the written specification, appended claims, and attached drawing, wherein;

FIG. 1 is partially sectioned elevation view of a tool embodying the invention as held in a hole of a workpiece;

FIG.) is an isometric view of the tool positioned to reflect light from a specific'flaw in the wall of the hole, and

FIG, 3 is a partially sectioned elevation view of the tool as inserted into a workpiece bore to function as a dimensional gauge.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to'FIG. I, there is disclosed an example of a workpiece having a cavity, hole, depression, chamber or bore whose walls require inspection to determine if they are flawed or whether some structure on the walls is formed or positioned correctly. Specifically, workpiece I has an internal bore 2 with walls 3 requiring inspection.

The bore 2 has an opening 4 into whichthe inspection tool embodying the invention is inserted. With the tool, a peripheral section of the walls is viewed by eye 5. Positioning the tool along the walls will develop the image of the walls 3 available to eye 5 until the complete area of the bore walls 3 is viewed.

The tool is basically characterized by body 6 which is provided with a reflective surface 7. Surface 7 is polished or plated to provide a mirror which will reflect all light received from walls 3 to eye 5. Surface 7 is inclined at 45 to the horizontalto reflect the image of the walls 3 to eye 5. Movement of body 6 along the bore will transmit images of that portion of walls 3 to eye 5 which are opposite the reflective surface of body 6.

Body 6 is manually positioned, although this is not a limitation of the invention. Handle 8 is bolted to body 6. Extending up from body 6, and symmetrically attached,relative reflective surface 7, handle 8 is a convenient means whereby body 6 is positioned along bore 2 to provide the desired view of its H walls 3.

Handle 8 includes a flashlight with a switch 9. The bulb 10, as a source of light, is held in fixed relation to the body 6 and its reflective surface 7. Specifically, the bulb 10 is spaced from body 6 and casts its light on walls 3. The light reflected from walls 3 is received by surface 7 and the image of the walls reflected to eye 5. Y V

The mechanical arrangement of flashlight 8, bulb 10 and body 6 is completely disclosed by the drawing. A clear plastic portion 11 of handle 8 is bolted to body 6 so the flashlight 8 and bulb 10 within the plastic portion 11- are symmetrical with respect to reflective surface 7.The combination provides a compact tool which is readily manipulated by hand. It is thrust into the opening of a cavity, chamber, hole or depression whose walls require inspection and reciprocated to scan the internal walls.

FIG. 2 discloses how a specific defect, or flaw, 12 in the walls 3 appears to eye 5 as an image on surface 7. Thus the invention produces a handy, flexible viewing device for surfaces not readily viewable directly. The embodying apparatus is a vast improvement over the present arrangement of a small dental mirror and separate flashlight which are fumbled awkwardly about in a time-consuming effort to comprehensively inspect internal walls.

FIG. 3 discloses the tool embodying the invention simultaneously utilized as a dimensional gauge. Many times the bore having walls to be inspected visually has a crosssectional dimension which needs to be checked. A bore 13 in a workpiece l4is disclosed with the body 6 positioned in it. As a go dimensional gauge, the tool can simultaneously function to provide the image of the walls l5which is also desired.

CONCLUSION Body 6 has the shape of a conical frustum.The particular relation disclosed, between the size of the end of portion 11 and the attached end of body 6, is that they are of the same area. However, they could be different.

The handle 8 could be used with a body 6 .of different dimensions than disclosed and carry out the function of the invention.

To form body 6 as a dimensional gauge, it could be quite large for the handle 8 disclosed. Such a body could be lightened by hollowing it out.

The basic concept is the provision of a body with a reflective surface embodied with a light-source handle. Secondarily, the concept includes the use of the body as a dimensional gauge at the same time it provides the inspector an image of walls.

From the foregoing it will be seen that this invention is one well adapted to attain all of the ends and objectshereinabove set forth, together with other advantages whichare obvious and which are inherent to the method and apparatus.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the invention.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter set forth above or'shown in the accompanying drawing is to be interpreted as illustrative and not in a limiting sense.

The invention having been described, what is claimed is:

l. A tool for inspection of the interior surface of a cylinder, including,

a body having a reflective external surface in the form of the right frustum of a cone,

a transparent housing secured to said body at the bodys smaller end as a supportive structural element for the y.

a light source contained within said transparent housing to illuminate the interior cylindrical surface during inspection, whereby light is reflected from said interior cylindrical surface to the reflective surface of the body and to an observer, and

3 ,610,763 3 4 a handle means attached to the transparent housing and 2. The tool of claim l,wherein,

elongated axially with the axis of the cone and having a the diameter of the larger end of the reflective frustum has a diameter substantially equal to the diameter of the diameter substantially equal to the interior diameter of smaller end of the frustum. the cylinder to function as a gauge thereof. 

1. A tool for inspection of the interior surface of a cylinder, including, a body having a reflective external surface in the form of the right frustum of a cone, a transparent housing secured to said body at the body''s smaller end as a supportive structural element for the body, a light source contained within said transparent housing to illuminate the interior cylindrical surface during inspection, whereby light is reflected from said interior cylindrical surface to the reflective surface of the body and to an observer, and a handle means attached to the transparent housing and elongated axially with the axis of the cone and having a diameter substantially equal to the diameter of the smaller end of the frustum.
 2. The tool of claim 1, wherein, the diameter of the larger end of the reflective frustum has a diameter substantially equal to the interior diameter of the cylinder to function as a gauge thereof. 